Refrigeration by means of carbon dioxide in solid state



Sept. 20,- 1932. .1. s. WAGNER f @1,878,042

REFRIGERATION BY MEANS OF CARBON DIOXDE IN SOLID STATE Filed Jan. 18. 1930 l5 Np/ 16 Patented sept. 2o, 1932- UNITED STATES PATENT oEFicE JAMES S. WAGNER, 0F CHARLEROI, PENNSYLVANIA, ASSIGNOR 0F ONE-FIFTH T0 GEORGE .W. KING, 0F FAYETTE COUNTY, PENNSYLVANIA; ONE-FIFTH TO MCCLELLAND HIXENBA/UGH, ONE-FIFTH T0 HARRY I. RAY AND ONE-FIFTH TO CHARLES S. BATEMAN, ALL 0F CHARLEROI, PENNSYLVANIA REFEIIGERATION BY MEANS 0F. CARBON DIOXIDE IN SOLID STATE Application led January 18, 1930. Serial No. 421,714.

is particu arly adapted tocool refrigerator-- cars, ice-cream delivery wagons, and other convevances for transporting perishable commodities. Y

The refrigerating unit in which the meth- 0d is effectively conducted is shown in the' accompanying drawing. Fig. I shows in side elevation a motor truck, the body portion of which is in structure a closed refrigerating box, icluding the refrigerating unit. Fig. II is a diagrammatic illustration of the refrigerating unit, showing fragmentarily, and partly inside elevation and partly in crosssection, the container for the refrigerant.

Referring to the drawing the refrigerating unit includes a refrigerant chamber to which the reference numeral 2 is applied. Essentially the external walls of chamber 2 are of heat-conducting material, and of such strength as to withstand great internal pressures accordingly, these walls will ordinarily be of metal. chamber 2 forms a seat 3 around the mouth 4, and a cover 5, provided with a suitable gasket 6, conveniently of rubber, serves to close hermetically the mouth 4. A keeper-bar 7 overlies the cover 5, and is inserted at each end in an eye-lug 8, each of which eye-lugs is' xed to the walls of chamber2. A. plurality of clamping-screws 9 extends through the keeper-bar, and in threaded, engagement therewith. Thev clamping-screws are rotated to bring their lower ends with great preure against the cover 5. The keeper-bar and its associatedv screws 9 assure tight seating of the cover to seal hermetically the chamber' 2 and maintain highv pneumatic pressure within.

To introduce solidified refrigerant into the chamber 2, the clamping-screws 9 are rotated to move them out of contact with the The vrim of the side-walls of cover 5, and the -ends of the keeper-bar are removed from the eye-lugs 8. The cover 5v is then easily removed. The refrigerant 10 solidified carbon dioxide) is then placed in t e chamber, as illustrated, and the cover and keeper-bar returned to theirv positions of closure. Advantageously, partitions 11 are pro vided, to insure even distribution of the refrlgerant within the chamber 2, under such conditions as-the jolting incident to transportation by delivery wagon.

It is important that the metal of which the walls of chamber 2 are formed' be of high heat conductivity (such a metal as steel), to enhance heat absorption from the body of air surrounding the chamber, and to enhance the conduction of the so abstracted heat to the refrigerant l0. Indeed, the metal Walls of the chamber may be lformed with integral, outstanding ins 20 to aid such heat absorption. The heat absorbed by the solid carbon dioxide 10 effects its sublimation; that is to say, the heat promotes the immediate conversion of the refrigerant 10 from a solid to a gaseous state. Gaseous carbon dioxide so liberated builds up a high pressure in chamber 2. Although, as will presently appear, the gaseous carbon dioxide is not absolutely confined Within the chamber 2, the gas does exist therein under exceedingly high pressures.

It will be noted that the refrigerant chamber is in its structure adapted to meet such conditions of pressure. That is to say, the walls are formed of strong heat-conducting metal, reinforced'transversely by the partitions 11, andthe cover 5 and the keeper-bar 7 afford' means for hermetically closing the mouth 4 to withstand great internal pressure. The evaporation of the solidified carbon dioxide proceeds within chamber 2 until the liberated gaseous carbon dioxide exists under pressure, but, as mentioned above, the gas is not absolutely confined. An escape of the gas is provided for, through a small orifice, whose effective area may advantageously be controlled by an adjustable valve, and the escaping gas 1s caused to expand into a conduit, which conduit also is so arranged as to absorb heat from the same body of air,l and so to further the refrigerating eiect. To this end,

. .predetermined value. The cold escaping gas.v

the refrigerating apparatus includes a 0001-' ing coil 13 in communication with chamber 2. An adjustable valve 14 controls such communication, and in regulating this valve, the` pressure Within the chamber 2 may be ycointrolled, the quantity of escaping gas may be varied, and f the refrigerating effect may, therefore, 4be minutely regulated. This valve may be and preferably will be an automatic pressure-regulating valve, to maintain -the pressure in chamber 2 alwaysat a fixed' and passes through the conduit 13'to the open air,

and in so doing draws heat throu h the wall of the conduit from the confined ody of air which is to be kept cool.' The conduit o r cooling coil 13 is advantageously formed of hi h heat-conductingmaterial, such as copper. o much of the conduit as protrudes beyond the walls of the cooledchamber and into the open air lmay advantageously be formed of material of low heat conductivity, of rubber, for exgreat internal pressure and a removable cover adapted to be secured in hermetically tight closure upon said container Walls, the said container being provided interiorly with transverse partition Walls preventive of shifting of a'contained charge of refrigerant, and the coil being in communication with the container, the said coil at its intake end being equipped with a manually operable pressure control valve and at its delivery end vwith a check valve.

In testimony whereof I have hereunto set my hand.

JAMES S. WAGNER.

ample.' .Referring to Fig. I, the protruding end 16 of the conduit may be of rubber.

Adjacent the outlet end of the conduit 13 a check-valve 15 is'included, to prevent atmospheric air from entering the conduit. It

is to be understood that an orifice of fixed' t size, in-place 4of the Valve 14, may be so proportioned as to eHect expansion of thecarbon dioxide gas, as it passes from the chamber 2 into the conduit 13; and an adjustable valve, may be substituted for the check-valve 15. Regulation of such a valve so situated will then be effective tocontrol the diil'erence in pressure existing on opposite sides of the construction arranged at' 14,.between the chamber 2 and the conduit. Manifestly, such regulation of pressure will control the rate of ilow of the gaseous carbon dioxide from chamber 2.

In Fig'. I, I have shown the refrigerating unit installed inthe refrigerator body 1 of a motor truck. The refrigerant chamber 2 is secured in place Within the heat-insulated body 1, conveniently against a side wall of the body, 'as indicated 1n dotted lines. The

cooling conduit l13 is secured conveniently to the inner surface of .the roof of the refrigerator body, and the outlet end' of the conduit projects, at 16, into the atmosphere.

Carbon dioxide in solid condition has in recent years become a commodity sold in bulk. I The apparatus here described is designed for conducting `inmaterial. of strength to withstand ist 

